The objectives of the program are to study the different phases of circulatory dynamics and their control. Emphasis is being placed on both normal and abnormal control, since many diseases such as hypertension, shock, edema, neurogenic and endocrine disorders, and renal diseases are manifestations of abnormal circulatory control. Our efforts continue to be directed at the development of an overall quantitative mathematical model of the body's circulatory system, which is consistent with both normal physiology and pathological states. The mathematical analysis requires a quantitative description of the different systems and subsystems involved in circulatory control as well as the interrelationships among them. Data for the model is continually being updated with experimental data from our laboratory. Research is being conducted in two phases. The different laboratories within the Program Project are making appropriate measurements of various quantitative relationships within the circulatory system. Second, the data provided from animal experimentation is used to expand and redefine our mathematical analysis--particularly the current version of the large model of the overall control of the circulation. In turn, the mathematical analyses provide the basis for much of the new animal experimentation.